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package com.srcptit.javatrainning.thupt.b1;

import java.util.Scanner;

/**
 *
 * @author Autumn
 */
public class bai1 {
    public static int n;
    public static void main(String args[]){
        Scanner sc=new Scanner(System.in);
        n=sc.nextInt();
        hienthi();
      
                                           }
     public static int nguyento(){
         if(n<2)return 0;
         for(int i=2;i<=Math.sqrt(n);i++)if(n%i==0)return 0;
         return 1;
                                   }
     public static void hienthi(){
         if(nguyento()==1)System.out.println("la so nguyen to");
         else System.out.println("khong la so nguyen to");
                                  }
     
}
